Your professor says your essay reads like AI

The instructors in r/Professors are mostly not running your paper through a detector — many say they do not trust them. What they describe is reading, and the feeling two sentences in that something is off. When one of them asked the sub to list the tells, the answers were unusually specific.

The tells they named

• "It's not X, it's Y." The most-named pattern by a distance. One instructor only had to write the slogan it sounds like — it's not delivery, it's DeGiorno — and the thread recognised it at once. Another said the construction haunts their marking periods.
• Too polished and empty at the same time. A little too smooth, formal and stiff, above the level of the writer, and impersonal. Several gave almost the same sentence for it.
• One rhythm, one paragraph length. Short sentences for emphasis, three-item lists, paragraphs of roughly equal size, no change of pace. Instructors said they feel the metronome before they can name it.
• Generalities where a life should be. Personal essays that talk about "patterns" and "growth" and contain no scene, no name, no specific behaviour. One teacher summarised it as plenty of words, very little meaning, delivered very professionally.
• An essay that never argues with itself. Two positions introduced and then politely merged, when the honest paper would make them fight.
• Citations that are real but wrong. Not invented sources so much as sources out of place: a paper cited for an idea it does not contain, or a reading that has nothing to do with the course.
• "We" in solo work. One instructor kept finding proposals written as "our proposed design will…" in a class where every proposal was individual.
• Identical openings. A thread that stopped us: forty essays, half of them beginning with the same sentence. The replies pointed out that this is plagiarism whether or not a machine was involved.

The finding nobody expected

One instructor described rewriting a letter of recommendation because, reading it back, it sounded generated. Their conclusion is the best summary of this subject we have found: the models learned from human writing, and now people are changing their writing to avoid sounding like themselves.

Others made a related point: students who read a lot of generated text begin to write like it on their own, without using it. One called it AI brain rot. Another said they genuinely cannot tell whether a paper was generated or simply written by someone whose reading is mostly machine text.

That case is why this site exists. "Was this written by AI" is not answerable from the text alone, and anyone who claims otherwise is guessing. "Which sentences carry the habits that make a reader suspect it" is a question with an answer.

What the threads say about detectors

The instructors who brought evidence were blunt. A 2023 review of fourteen detection tools found none of them reached acceptable accuracy. A Stanford study that year found detectors flagged more than half of genuine essays by non-native English speakers. OpenAI retired its own classifier after it caught roughly a quarter of generated text while flagging human writing as AI.

Then the consequence, from a thread title that says it all: students are now writing worse on purpose to stay under the threshold — short, flat, careful sentences, because good prose looks suspicious. That is what a bad measurement does to the thing it measures. It is also why we refuse to build one.

If you are already talking to a teacher about it

• Bring the process, not the percentage. Drafts, notes, outlines, document history. The instructors in those threads say a conversation about how the argument was built is what resolves these cases.
• Do not lead with a detector score. Several said a student citing one makes the case weaker.
• Be able to say why you chose a source and what you left out. That is what they ask, and it is hard to fake.
• If your prose does carry the patterns above, fix them — not to satisfy a tool, but because the essay gets clearer when the empty sentences go.

What we do, and what we will not do

We do not score authorship and we will not tell you how to beat a detector. We mark the sentences that carry the habits on this page, explain each one in a line, and rewrite the opening in a plainer voice so you can hear the difference between your sentence and a template.

More from the same reading: what Reddit says overall · college essays · fiction and fan writing